Well, the athlete that won the most medals in Olympic history is Larissa Latynina of the USSR who won 18 medals (9 gold, 5 silver, 4 bronze) in Olympic competition.
The one that was the most successful.
michael phelps
Badminton
swimming
birgit fischier.
Brazil
Vladimir Samsonov was the most successful European ping pong player at the Beijing Olympics. He is from Belarus that is located in Europes' Eastern block.
veryyy successful
Japanese
This was Mongolia's most successful Olympics, winning the total of five Olympic medals (2 silver and 3 bronze),
CALGARY WINTER OLYMPIC 1988 SEOUL KOREA 1988 SYDNEY BEIJING
Its usa but in some cases china will be better than usa